A tracheostomy is a surgical procedure in which an opening is formed through the anterior surface of the neck into the trachea. The opening is referred to as a tracheostoma. A tracheostomy tube can be provided to extend between the tracheostoma and the trachea. A tracheostomy is performed for example when there is a malfunction, such as a result from injury or disorder, in respect of the nervous system or the respiratory passages, which malfunction results in an incapacity to obtain enough air. An inferior lung capacity or need of respiratory treatment may also result in a tracheostomy.
A laryngectomy is a surgical procedure, used for example to treat a carcinoma, which involves removal of the larynx or voice box and creation of a tracheostoma. A consequence of the procedure is that the trachea is no longer connected to the pharynx but is diverted to the tracheostoma. After this procedure, normal nasal function is not possible. In a subject whose breathing functions normally, the nose and the mucous membrane lining of the nasal cavity perform important functions in conditioning inhaled air. The convoluted passages and rich blood supply serve to increase both the temperature and humidity of the inhaled air to minimise the differential in these parameters with those of the surface of the lungs. Normally some heat and moisture is also captured from exhaled air prior to its release to the atmosphere. The mucous lining of the nasal passages also serves to remove particulate matter, such as fine dust particles, pollutants and microorganisms, from the inhaled air, and the action of cilia transports mucous and any particles away from the lungs.
When a patient has received a laryngectomy, in effect all inhaled air enters the lungs via the tracheostoma, and the nose is effectively not involved in the inhalation process. Exhaled air may pass through the tracheostoma or, if a voice prosthesis has been fitted, the stoma can be occluded so that the exhaled air is diverted through the voice prosthesis into the pharynx and the mouth, enabling the patient to speak. It is desirable that the flow of the exhaled air be controlled by means of a tracheostoma valve. In these situations, the valve can be arranged to remain open during breathing but, with a small additional increase in exhaled air flow, can be closed to divert the airflow.
In this respect filter devices and breathing protectors have been developed to enable moisturizing of inhaled air and removal of small particles and bacteriological substances in said inhaled air. This is to resemble the functions of a nose. However, there are several complications related to the manufacturing of such devices. Firstly, the user of such devices is in need of good moisturizing and removal effect while keeping the size, such as the surface area, of the device as small as possible. Secondly, the moisturizing effect and removal effect is in need of large surface area, while not creating a too large resistance over the device. These criterions are contradictive, which the observant reader already has acknowledged. Also, a person with a laryngectomy has to hold his finger or thumb over these devices when wishing to speak, to thereby obstruct the air flow through the device and the stoma through the tracheal wall, which will burden the filter with undue contamination, due to transfer of impurities from the finger of the user to the filter.
U.S. Pat. No. 5,666,950 describes a device for filtering air that is to be breathed through a tracheostoma. This device comprises a pre-filter of electrostatically charged fibres, a first layer formed of activated carbon and a second layer of a hydrophilic material. The use of activated carbon provides filtration of small particles and absorption of gases, with a limited increase in the resistance to airflow through the device. However, the finger or thumb of the user will influence the antibacterilogical effect of the bacteriological filter in a negative way, since it is unreasonable to demand a totally bacteriological free condition of said finger or thumb, which means that said filter will be contaminated by time. Furthermore, the device according to U.S. Pat. No. 5,666,950 does only achieve an antibacteriological effect of approximately 50%, since the surface area of the bacteriological filter is restricted to the surface area of the opening communicating with the surroundings, while providing an adequate resistance over the device.
U.S. Pat. No. 5,487,382 describes an artificial nose with a housing and a hydrophilic filtering disc, further comprising a cap, which can be moved up and down to open/close windows in the housing. The artificial nose according to U.S. Pat. No. 5,487,382 has to be actively moved from an open position to a closed position and vice versa, and has a very limited antibacteriological effect.
Hence, an improved breathing protector would be advantageous and in particular a breathing protector allowing for increased antibacteriological effect and an excellent moisturizing effect, while also providing the possibility to a patient to keep the breathing protector closed, such as during speech, without undue contamination of the filter by holding a finger or thumb over said opening during the entire period of speech. It would also be advantageous to obtain a breathing protector with an increased antibacteriological effect and the possibility for a patient to keep the breathing protector closed, such as during speech, without undue contamination of the filter by holding a finger or thumb over said opening, which breathing protector not is persued by having to be actively moved from an open position to a closed position and vice versa. It would also be advantageous to provide a breathing protector allowing for an increased antibacteriological effect and an excellent moisturizing effect, while still providing a small breathing protector with a satisfactory resistance over said breathing protector.